There are many “critical infrastructures”, such as those destined to transportation, which demand surveillance and protection and for which plenty of measures have been deployed, essentially based on video-surveillance by means of electro-optical sensors such as daylight video cameras and night vision infrared cameras. Unfortunately all these sensors become useless in case of thick fog, heavy rain, dense smog and similar prohibitive factors, because the particles in air suspension disperse the light rays, also the infra-red ones.
Then to explore such invisible scenarios only microwaves can be used, and radars are the best known solution. They are complex transmitter-receiver devices, irradiating electromagnetic power into a large frequency band; for this reason unfortunately they are considerable sources of electromagnetic noise, at the point that more identical radars cannot work together without disturbing each other, unless they be distant enough or used distant frequency bands: the availability of which is limited anyway, and therefore is limited also the number of identical radars let working together in a same area. This means that existing radars cannot be deployed independently at will as it happens for cited video cameras.
The first aim of the invention is to disclose a plurality of radars that can be deployed at will, as allowed with ordinary video cameras, without problems of interference or disturbances. This result introduces a new family of sensors, that we may call “microwave cameras” or “radar cameras”, in analogy with the common video cameras for the easy application everywhere at will, nevertheless distinctive for exploring also invisible scenarios in bad weather even with zero visibility.
The second aim of the invention is to become a complete surveillance system, which is truly “distributed”, “adaptive” and “all weather”, using combinations of “video cameras” and “microwave cameras” as before specified realizing multispectral compact devices, suitable to be deployed at will in multiple configurations, without interference problems and without limitations about their number, coverage, geometry, extension and application.
Hence the invention overcomes all similar solutions of the past, by introducing a scalable monitoring system able to detect both nearby and distant objects, measure their position and provide intelligent data elaboration, by means of small compact devices easily applicable at will to structures of any geometry and size. In fact the whole system can be broken down into self-contained parts suitable for any installation, since comprising a radar system that can be decomposed at will. The detachment handles the volatile nature of microwave radar signals and their complex control, satisfying the triple condition that said self-contained parts work autonomously wherever, are integrated like a whole and perform correlation in “real time”: what is comparable to “move the biological ears” from a head long away and however maintain their functionality with the rest of the body.
In practice this feature discloses a new type of “distributed adaptive radar” having the original capability of expanding at will, to survey areas of any geometry, shape and extension, for both fixed and mobile structures of any size and number, in order to satisfy several applications previously unimagined, as explained below.
Such a non-conventional architecture comes out from specific properties of composition, decomposition and adaptiveness, not included in any of prior art documents.
Hence the invention represents a significant evolution in the specific technique of the same field and with respect to the other patents, also by the same inventor, such as the IT 1222297, IT 1277302, U.S. Pat. No. 5,045,856, EU 396 611. In fact any traditional radar is meant like a stand alone “monolithic” equipment, performing a limited and centralized coverage by means of the classical scanning antenna, without the capacity of spatial decomposition and composition as introduced by the invention. Due to this capacity, instead, the invention performs a de-centralized coverage, potentially unlimited, from many points of view, then “distributed” and “adaptive” for any structure, platform and application.
In other words, a conventional “monolithic” radar system now becomes, according to the invention, split in a “plurality” of smaller radars: each one operating either autonomously or jointly, each one being not cumbersome, not heavy, not showy and therefore suitable to be installed and hidden and scattered and spread at will along extended fixed structures, roads, bridges, channels, rails, tunnels et cetera, for any type of surveillance and relevance on land, sea or air, along lines, surfaces and volumes of all kinds and shapes; and also can be installed on moving structures, vehicles, trains, boats, aircraft et cetera for anti-collision purposes, safe driving, inspections at a distance, ground investigations, info-mobility; and can also become portable and even wearable.
All this variety of applications is of course impossible with conventional stand alone radars, which are all “monolithic” devices even if internally made up by modules or mini-radars performing elementary functions, because such modules stay all together inside the same assembly and are synchronized all at once, and therefore they are not independent, not self contained, not autonomous, not suitable to be “distributed” at will over long distances.
For instance, the patent US2006/197699 mentions transmitting and receiving modules which are the front-end parts of an active electronically scanned antenna; all said modules share a common local oscillator and also a reference clock that synchronizes them, to the purpose of adding up their elementary contributions all at once to produce a greater one, that is the one pertaining to one antenna device, suitable for one radar apparatus, which consequently results like a conventional “monolithic” apparatus, stand alone, clearly unable to satisfy applications spatially “distributed” and “adaptive” as those attended by the invention.
Also WO 2009/019191 deals with a modular radar system composed by a plurality of mini-radars which, as before, are synchronized by a centralized unit through a common clock signal; being obvious that each one module creates its own radar independent pathway and that the synchronization of the modules drives them all at once so as to finally appear like a single electronically scanned antenna; of course such antenna may be a part of a radar, and vice versa this one may include said modules; therefore such a radar globally turns out to be a “monolithic” apparatus again, being not a “distributed” apparatus according to the present invention, which is based on a different architecture with parts capable to operate autonomously, separated also by long distances, without a common synchronization.
U.S. Pat. No. 5,517,197 considers the modular architecture of a radar provided with a transmitting receiving antenna, that is again a “monolithic” apparatus, without any possibility of decomposition or combination with other similar devices in order to constitute a “distributed” and “adaptive” radar system like the invention.
For the rest, there is a substantial difference with all the innumerable patents simply adding a traditional video camera with a traditional radar or microwave sensor, since the present invention is based on the non-conventional architecture here disclosed with specific properties of composition, decomposition and adaptiveness.